Unlike Irene Dunne, Katharine Hepburn and Barbara Stanwyck, who were stars virtually from their start in movies, Lombard worked long for her success, appearing in films regularly, including many shorts, beginning in the mid-1920s.
In a sharper movie (and let's shoot for the moon here -- Barbara Stanwyck as the con woman in "The Lady Eve"), Diana would play Bateman's smug executive for a sucker and take him for everything he's got.